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Brignone MS, Lanciotti A, Michelucci A, Mallozzi C, Camerini S, Catacuzzeno L, Sforna L, Caramia M, D’Adamo MC, Ceccarini M, Molinari P, Macioce P, Macchia G, Petrucci TC, Pessia M, Visentin S, Ambrosini E. The CaMKII/MLC1 Axis Confers Ca2+-Dependence to Volume-Regulated Anion Channels (VRAC) in Astrocytes. Cells 2022; 11:cells11172656. [PMID: 36078064 PMCID: PMC9454758 DOI: 10.3390/cells11172656] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 08/18/2022] [Accepted: 08/24/2022] [Indexed: 11/30/2022] Open
Abstract
Astrocytes, the main glial cells of the central nervous system, play a key role in brain volume control due to their intimate contacts with cerebral blood vessels and the expression of a distinctive equipment of proteins involved in solute/water transport. Among these is MLC1, a protein highly expressed in perivascular astrocytes and whose mutations cause megalencephalic leukoencephalopathy with subcortical cysts (MLC), an incurable leukodystrophy characterized by macrocephaly, chronic brain edema, cysts, myelin vacuolation, and astrocyte swelling. Although, in astrocytes, MLC1 mutations are known to affect the swelling-activated chloride currents (ICl,swell) mediated by the volume-regulated anion channel (VRAC), and the regulatory volume decrease, MLC1′s proper function is still unknown. By combining molecular, biochemical, proteomic, electrophysiological, and imaging techniques, we here show that MLC1 is a Ca2+/Calmodulin-dependent protein kinase II (CaMKII) target protein, whose phosphorylation, occurring in response to intracellular Ca2+ release, potentiates VRAC-mediated ICl,swell. Overall, these findings reveal that MLC1 is a Ca2+-regulated protein, linking volume regulation to Ca2+ signaling in astrocytes. This knowledge provides new insight into the MLC1 protein function and into the mechanisms controlling ion/water exchanges in the brain, which may help identify possible molecular targets for the treatment of MLC and other pathological conditions caused by astrocyte swelling and brain edema.
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Affiliation(s)
| | - Angela Lanciotti
- Department of Neuroscience, Istituto Superiore di Sanità, 00169 Rome, Italy
| | - Antonio Michelucci
- Department of Chemistry, Biology and Biotechnology, University of Perugia, 06123 Perugia, Italy
| | - Cinzia Mallozzi
- Department of Neuroscience, Istituto Superiore di Sanità, 00169 Rome, Italy
| | - Serena Camerini
- Core Facilities (FAST), Istituto Superiore di Sanità, 00169 Rome, Italy
| | - Luigi Catacuzzeno
- Department of Chemistry, Biology and Biotechnology, University of Perugia, 06123 Perugia, Italy
| | - Luigi Sforna
- Department of Chemistry, Biology and Biotechnology, University of Perugia, 06123 Perugia, Italy
| | - Martino Caramia
- Department of Chemistry, Biology and Biotechnology, University of Perugia, 06123 Perugia, Italy
| | - Maria Cristina D’Adamo
- Department of Medicine and Surgery, LUM Giuseppe Degennaro University, 70010 Bari, Italy
| | - Marina Ceccarini
- National Centre for Rare Diseases, Istituto Superiore di Sanità, 00169 Rome, Italy
| | - Paola Molinari
- National Centre for Drug Research and Evaluation (FARVA), Istituto Superiore di Sanità, 00169 Rome, Italy
| | - Pompeo Macioce
- Department of Neuroscience, Istituto Superiore di Sanità, 00169 Rome, Italy
| | | | | | - Mauro Pessia
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, MSD2080 Msida, Malta
- Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain P.O. Box 17666, United Arab Emirates
| | - Sergio Visentin
- National Centre for Drug Research and Evaluation (FARVA), Istituto Superiore di Sanità, 00169 Rome, Italy
| | - Elena Ambrosini
- Department of Neuroscience, Istituto Superiore di Sanità, 00169 Rome, Italy
- Correspondence: ; Tel.: +39-06-4990-2037
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